A new study published in the science journal Standing Waves shows that RF signals are disappearing at an alarming rate. Some scientists are going so far as to say that if action is not taken immediately, the airwaves could be completely silent by 2040.
The study’s chair, Dr. Bunsen Honeydew said, “We looked at daily activity on the HF bands from 3.5 to 29 MHz over the last 11 years. For a while the bands were showing healthy growth with plenty of activity, but in just the last five years signals have become much weaker and some have even disappeared completely. Worse hit has been the 10 meter band where we haven’t observed a signal for over two years… the extent of the devastation is breathtaking.”
But what is causing it? Scientists have a few theories but the main culprit seems to be that there are simply too many antennas absorbing a limited supply of RF. As this simple formula shows, RF is depleted at a rate inversely proportional to the square of the distance between any two stations:
Scientists warn that, as cos (1/x) increases, we risk reaching “the point of no return” where RF levels will never recover.
But what does this mean to the average ham? The short answer is we must all help conserve RF. Where hams used to just have one radio, it is now common to own three or even four radios, each with an RF absorbing antenna.
Of course, some of the worst contributors to the crisis are the so-called “Big Gun” stations. These use aluminum farming techniques that have gotten way out of control… covering acres of land with multiple towers reaching up to 100 feet and scooping up every signal that goes by.
The International Amateur Radio Union (IARU) and member societies like ARRL are calling for urgent action and plan to table a number of propositions at the next WARC meeting in Geneva. Among them would be a limit on antenna farming, a program for offsetting RF absorption by deploying more transmitters around the globe, and requiring hams to turn off their receivers when not really listening.
Perilous times.
- Adrian VE7NZ reporting
Hello Adrian, thank you for this enlightening article and for drawing attention to this growing problem. I understand that this may lead to an RF preservation tax much like the carbon tax that is now in place. I for one will be installing reflectors on all my antennas, when they are not in active use, to bounce the RF back into the aether.
I will certainly include this timely article on page 13 of the next issue of The Communicator in the hope that it will spur others into action before its too late.
John VE7TI
Editor
‘The Communicator’
https://ve7sar.blogspot.ca
I am guilty of absorbing too much rf. I will immediately begin to remove my five towers, multiple mono band full size yagis 160-2m and restructure my amateur radio hobby to use only the internet for QSOs!
ReplyDeletede Ted VE9AQM
Three simple, verified, solutions are:
ReplyDelete1) Disconnect all the antenna cables at the radio. The SWR will send the RF back up the line to be re-radiated.
2) If you have multiple pairs of antennas, cross-connect them so signals received on one will be radiated by the other, hopefully in another direction which may have less RF density.
3) Terminate your antenna into a carbon resistor load placed under your coffee cup to keep it warm and while cutting down on your carbon footprint.
[Note: Solutions 1 & 2 raised my noise floor by an average of 4.13 dB. Solution 3 required experimentally determining the proper value; a 133 Ohm resistor keeps my coffee at 185 degrees. Your mileage may vary. Be sure to use a non-inductive resistor. Wirewound resistors will produce the same result as solution 1.]
Ron WA5QBA